1. Technical Field
The present invention relates to a technology for processing a moving image, which is generated by photographing a character string, to read characters in the moving image.
2. Related Art
As to an OCR application incorporated in an information processing device, such as a mobile phone, which has a moving image photographing function, there is well known an OCR application that selects a frame suitable for recognition processing while processing the moving image of the character string in units of frames, and outputs the character string read from the image of the selected frame.
For example, in the description of Patent Document 1, a change to the previously-captured image is extracted every time the image is captured, character recognition processing is performed using the image in which the extracted change amount becomes lower than or equal to a predetermined permissible value, and a recognition result is output under the condition that a degree of similarity of a recognition target image to a character model determined to correspond to the recognition target character string in the character recognition processing is greater than a predetermined reference value (see Paragraph Nos. 0025 to 0046, FIG. 4, and the like of Patent Document 1).
In the description of Patent Document 2, an evaluation value is obtained to determine whether every frame image is suitable for the character recognition, and the character recognition processing is performed when the frame in which the evaluation value is greater than a threshold is discovered, or the character recognition processing is performed using the frame image in which the maximum evaluation value is obtained. The evaluation value is calculated from parameters such as a shutter speed, an aperture value, and contrast (see Paragraph Nos. 0027 to 0042 and the like of Patent Document 2).    Patent Document 1: Japanese Unexamined Patent Publication No. 2008-250818    Patent Document 2: Japanese Unexamined Patent Publication No. 2009-88944